Energy conservation is an increasingly important consideration for businesses and individuals alike as energy becomes more expensive. Both heating and cooling represent a major source of energy expense, and so alternative methods of heating and cooling are becoming more popular and viable.
Geothermal ground loop heating is used to defray costs associated with heating (or cooling) air and water within a building by taking advantage of the natural temperature differential between the surface air and underground. Such systems typically include a ground loop of underground pipes largely situated below a permafrost layer such as in the earth or in a lake bed or the like, a building loop of pipes largely situated within a structure such as a building, and a fluid pump to pump a heat transfer fluid through the ground and building loops. Within the building loop, the transfer fluid is pumped through a heat exchanger where heat is extracted and used in the building. The fluid is also pumped through underground pipes of the ground loop where it absorbs more heat and carries it back into the building. A similar process can be used for cooling, the transfer fluid being used to move heat out of the building and into the cooler ground.
The fluid pump maintains a generally even and constant flow of the transfer fluid through the entire system, even during times that heat is not being exchanged, such as when the system is otherwise idle or the building is not occupied, for example. Variable-speed drives can be installed to reduce the pump speed and save energy during such idle and unoccupied periods, but the pump still needs to run at some minimum speed on a continuous basis just in case one or more of the heat exchangers is activated, so that the exchangers can use the heat capacity of the fluid.